Process for development of multilayer color photographic materials

ABSTRACT

Method of processing a silver halide multilayer color photographic material which comprises the incorporation of a mercaptotriazole compound into one of the processing solutions. Such incorporation causes selective inhibition of the development of the uppermost emulsion layer, resulting in a developed material possessing improved, balanced contrast.

United States Patent Inventors Reiichi Ohi;

Haruhiko Iwano; Tadao Shishido; lsao Shimamura, all of Kanagawa, Japan App]. No. 842,011

Filed July 15, 1969 Patented Oct. 26, 1971 Assignee Fuji Photo Film Co., Ltd.

. Kanagawa, Japan Priority July 15, 1968 Japan PROCESS FOR DEVELOPMENT OF MULTILAYER COLOR PHOTOGRAPHIC MATERIALS 17 Claims, No Drawings U.S. Cl 96/66 R, 96/22 lnLCI G03c 5/50,

G030 5/52, G03c 5/30 Assistant ExaminerAlfonso T. Suro Pico Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak ABSTRACT: Method of processing a silver halide multilayer color photographic material which comprises the incorporation of a mercaptotriazole compound into one of the processing solutions. Such incorporation causes selective inhibition of the development of the uppermost emulsion layer, resulting in a developed material possessing improved, balanced contrast.

PROCESS FOR DEVELOPMENT OF MULTILAYER COLOR PHOTOGRAPI'IIC MATERIALS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method of developing a color photographic material, in particular, by the use of a compound available in a high temperature rapid processing.

2. Description of the Prior Art Multilayer color photographic material generally has at least three kinds of silver halide emulsion layers, each differing in color sensitivity, superimposed on a support, for example, a blue-sensitive emulsion as uppermost layer, yellow filter layer, green-sensitive emulsion layer and red-sensitive emulsion layer.

Of late, the method of developing color-sensitive materials has undergone a change, particularly in that the developing temperature has been raised to shorten the developing time. This is ordinarily called the high temperature rapidprocessing method. One of the difficulties encountered in the development of multilayer materials, especially when the development is carried out at high temperatures, is the overdevelopment of the uppermost emulsion layer before the lower emulsion layers are completely developed. The overdevelopment, which is caused primarily by the excessive concentration of the developer in the uppermost layer, results in disproportionate image density in that layer as compared to the remaining layers.

To overcome this disadvantage, it is known to add a development inhibitor, which inhibits the overdevelopment of the uppermost layer, to the processing solution, but the addition of commonly used development inhibitors, such as for ex ample 6-nitroisoindazole, is not always suitable for this purpose since the effect extends to the lowermost layer as well as the uppermost layer.

In order to avoid this disadvantage, it is known to add an acylaminophenyl mercaptotetrazole compound to a development solution (cf. US. Pat. No. 3,295,967), so that the development of only the uppermost layer is selectively inhibited and development throughout all of the layers is well balanced. However, the difficulty of this method is that the mercaptotetrazole compound disclosed in this patent is synthesized from thiophosgene which is generally hard to obtarn.

SUMMARY OF THE INVENTION It is the principal object of the invention to provide a method using a mercaptotriazole compound as a development inhibitor for the uppermost layer in the high temperature rapid-processing treatment of a silver halide multilayer color photographic material.

We have discovered that selective inhibition can be achieved by adding a mercaptotriazole compound, which can readily be synthesized, to a preprocessing solution or to a developing solution.

DETAILED DESCRIPTION OF THE INVENTION In the high temperature rapid-processing method of this invention, a mercaptotriazole compound is added to a developing solution or to a preprocessing solution prior to development, whereby to suppress selectively the progress of development of only the uppermost layer of multilayer color-sensitive material, to inhibit overdevelopment of the uppermost layer, thereby improving the color balance and image quality ob tained.

A particular advantage of the present invention lies in the ability to process at a temperature of from 30 to 70 C. when using a compound of the invention.

The above preprocessing solution is usually a prehardening bath consisting of an aqueous solution containing one or more aldehydes having the ability to harden gelatin, a component of the photographic emulsion. Examples of these are formaldehyde, glyoxal, succinaldehyde and glutaraldehyde. This solution also would normally contain a salt such as sodium sulfate, a buffering agent such as borax, acetic acid, sodium acetate, sodium hydroxide, sodium carbonate, sulfuric acid or boric acid and a fog inhibitor such as an alkali metal halide.

The first developing solution of a color reversal film is an aqueous solution containing one or more developing agents such as hydroquinone, l-phenyl-3-pyrazolidone or N-methylp-aminophenol, to which may be added a salt such as sodium sulfate, a buffering agent such as borax, boric acid, sodium hydroxide or sodium carbonate and a fog inhibitor such as an alkali metal halide.

The color-developing solution of a color negative film or color paper is an alkaline aqueous solution containing one or more p-phenylenediamine derivatives such as N,N-diethyl-pphenylenediamine sulfite, N,N-diethyl-Ii-methyl-p-phenylenediamine hydrochloride, 4-amino-3-methyl-N-ethyl-N- methanesulfonamideethylaniline sulfate, 4-amino-3-methyl- N-ethyl-N-hydroxyethylaniline sulfate or N-ethyl-N-hydroxyethyl-p-phenylenediamine sulfate, to which may ordinarily be added a salt such as sodium sulfate, a buffering agent such as sodium hydroxide, sodium carbonate or sodium phosphate and the usual fog inhibitor such as an alkali metal halide.

The object of the invention can be achieved by adding, to one or more of the above processing solutions, a mercaptotriazole compound represented by the following formula (wherein R represents hydrogen, amino or wherein R represents alkyl such as methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl and the like).

The compounds of the present invention are used in connection with the color processing of multilayer photographic materials well known in the art. Such materials generally comprise a support of cellulose ester, paper or other suitable base having coated thereon a red-sensitive emulsion layer containing a cyan-forming coupler, a green-sensitive emulsion layer containing a magenta-forming coupler and a bluesensitive emulsion layer containing a yellow-forming coupler. The couplers may be incorporated in any manner known in the art. The compounds of the present invention are, however, not limited in their use to the above-described multilayer material. The photographic material may contain fewer or more sensitive emulsion layers and may also contain conventional filter layers, inter layers, subbing layers, backing layers and overcoating layers. Further, for example, one or more of the emulsion layers may be free of incorporated couplers, the coupler or couplers for these layers being contained in the color developing solution.

According to the present invention, the mercaptotriazole compound is applied during processing to the image-exposed multilayer color photographic material so that this compound is present in the top silver emulsion layer (but not in the middle or bottom layers) during the negative development step of the color process.

The following are typical examples of the compounds used in the method of this invention. However, the compounds of this invention are not limited only to these examples, which 5 are presented for purposes of illustration.

Compound 1.3-merca.pt0-4-pheny1-1, 2, 4-triazole,

M.P. 172 G.

SH H C Compound 2.3-mercapto-5-methy-4-phenyl-1, 2, 4- triazole, M.P. 224 C.

s n C Compound 3.-5-ethyl-3-rnercapto-4-phenyl-1, 2, 4- triazole, M.P. 177

Compound 4.-3-mercapto-5-pentyl-4-phenyl-l, 2, 4- triazole, M.P. 137C.

Compound 6.3-mercapto-4-phenyl-5-undecyl-1, 2, 4-triazole, M.P. 103C.

Compound 7.4, 5-diethyl-3-mercapto-1, 2, 4-triazole, M.P. 148C.

?H /C zHs-N \N Compound 8.4-ethyl-3-mercapto-S-pentyl-1, 2, 4-

triazole, M.P. 86C.

Compound 9.4-ethyl-3-mcrcapto-5-phenyl-1, 2, 4-

triazole, M.P. C.

Compound 10.5p-an1inophenyl-4-ethyl-3-mercapto- 1,2,4-triazole, M.P. 245C.

SIH

Compound 11.5p-acetoan1idcphcnyl-4-cthyl-3- mercapto-1,2,4-triazole, M.P. 252C.

SiH C zHr-N N Compound 12.-5-p-caproamidcphcnyl-4-cthyl-3- mercapto-l,2,4-triazole, M.P. 216C.

Compound 13.4-ethyl-5-p-lauroamidephenyl-3- mereapto-1,2,4-triazole, M.P. C.

The above compounds can easily be synthesized by reaction of 4-substituted thiosemicarbazide and an acid anhydride (cf. British Pat. No. 766,380) or acid chloride (cf. Ohta and Toshima, Nippon Yakugaku Zasshi (Japan Pharmacology Journal)" Vol. 72, p. 376 (1952)), or by the reaction ofa substituted benzoyl hydrazine with a thioisocyanate.

The following are examples of the preparation of selected compounds to be used in the method of this invention.

EXAMPLE l-S-ethyl-B-mercapto-4-phenyl-1,2,4-triazole g. of 4-phenylthiosemicarbazide was dissolved in 80 ml. of pyridine and cooled with ice while stirring. 8 g. of propionyl chloride was then gradually added to this solution in drops. After the addition, the mixture was cooled with ice for 1 hour while stirring and then added to ice water and filtered. The resulting crystals were added to 80 ml. of a 10 percent aqueous solution of caustic soda, heated for 2 hours on a water bath, cooled, acidified with hydrochloric acid, filtered and recrystallized from ethanol to obtain 6 g. of the product as needles, melting at 177 C.

EXAMPLE ll 3-mercapto-5-pentyl-4-phenyll ,2,4-triazole 10 g. of 4-phenylthiosemicarbazide was dissolved in 80 ml. of pyridine and cooled with ice while stirring. 8 g. of caproyl chloride was then gradually added to this solution in drops. The reaction mixture was then processed as in example I and the resulting crystals recrystallized from ethanol to obtain 7 g. of the product as needles, melting at l 36-137 C.

EXAMPLE lll-4,5-diethyl-S-mercapto-l ,2,4-triazole 9 g. of 4-ethylthiosemicarbazide was dissolved in 50 ml. of pyridine and cooled .with ice while stirring. 10 g. of propionyl chloride was then gradually added to this solution in drops. The reaction mixture was then processed as in example I and the resulting crystals recrystallized from water to obtain 6 g. of the product as needles, melting at 148' C.

EXAMPLE lV-4-ethyl-3mercapto-S-phenyll ,2,4-triazole 9 g. of 4-ethylthiosemicarbazide was dissolved in 50 ml. of pyridine and cooled with ice while stirring. g. of benzoyl chloride was then gradually added to this solution in drops. The reaction mixture was then processed as in example I and the resulting crystals recrystallized from a mixed solvent of water and ethanol to obtain 9 g. of the product as needles, melting at 145C.

EXAMPLE V5-p-aminophenyl-4-ethyl-3-mercaptol ,2,4-

- triazole 12.5 g. of p-acetamidobenzoylhydrazine was dissolved in 100 ml. of ethanol. 10 ml. of ethylthioisocyanate was then added and the mixture refluxed for 2 hours. After cooling, the resulting crystals were filtered, added to ml. of 10 percent aqueous solution of caustic soda, refluxed for 2 hours on a water bath, cooled and acidified with hydrochloric acid and filtered. The resulting crystals were recrystallized from ethanol to obtain 9 g. of the product as needles, melting at 244-245C.

The compounds of this invention may be employed in a wide range of concentrations, i.e., from about 1X10" mol/liter to about 1X10 mol/liter. The optimum concentration depends upon a number of factors, for example, the particular compound used, composition of the treating solution, the activity of the developing solution, the treating temperature, the particular characteristics of the multilayer color-sensitive material, etc. The optimum concentration to be employed in any particular circumstance can be readily determined by methods well known in the art.

The following examples are given in order to illustrate the invention in detail without limiting the same.

EXAMPLE Vl A multilayer color film prepared by successively applying to a cellulose acetate support a gelatino iodobromide emulsion sensitive to red light, a gelatino iodobromide emulsion sensitive to green light, a yellow filter layer containing colloidal silver capable of absorbing blue light, and a gelatino iodobromide emulsion sensitive to blue light, was exposed on a sensitometer and then subjected to the following processes:

The processing solutions employed in the above series of processing steps had the following compositions:

Prehardening solution sodium hexametaphosphate l.0 g. sodium bisulfite 5.0 g. sodium pyrophosphate I50 g. sodium sulfate l50.0 g. potassium bromide 2.0 g. sodium hydroxide 0.l g. formalin (37%) I50 ml. water to make L000 ml. First developing solution N-methyl-p-aminophenol 5.0 g. sodium sulfite 70.0 g. hydroquinone 2.0 g. sodium carbonate monohydrate 41.0 g. potassium bromide 4.0 g. potassium thiocyanate Lo g. potassium iodide (0.l% aqueous solution) 10.0 ml. water to make 1,000 ml. Cyan color developing solution potassium bromide 3.0 g. -nitrobenzimidazole 0.03 g. potassium iodide (01% aqueous solution) l0.0 ml. sodium sulfite l0.0 g. sodium sulfate 60.0 potassium thiocyanate l.0 g. 4-amino-S-methyl-N-ethyl-N- hydroxyethylaniline sulfate 25 g. sodium hydroxide 3.0 g. l,S-dihydroxy-Z,6-dibromonaphthalene 2.0 g. monobenzyl-p-aminophenol 0.4 g. p-aminophenol hydrochloride 0.! g. water to make L000 ml. Yellow color developing solution sodium sulfite 10.0 g. potassium bromide 0.5 g. potassium iodide (0.l% aqueous solution) 25.0 ml. b-nitrobenzimidazole 0.! g. sodium sulfate 60.0 g. N,N-dietl\yl-p-phenylenediamine sulfite 2.5 g. sodium hydroxide 2.5 g. W-henlnyl-4-t p-tolucncsulfonamide) acetanilide L8 g water to make I ,000 ml Magenta color developing solution in the above color reversal developing treatment, a compound of the invention was added to the prehardening solution as tabulated below.

Addition amount Test No. Additive to prehardening (moi/liter) on no additive 6b 5-ethyl-3-mercapto-4-phenyl-l 2,4-triazole 1X10" 6c 3-mercapto-S-pentyl-4-phenyl-l,

2,4-trialole l X10 6d 4-ethyl-3-mercapto-5-phenyl- I .2.

4-triazole IX 10" 6e 4.5diethyl-3-mercapto-l,2,4

-triazole IX l Test No. Blue density (DBmax) Red density (DRmax) 6a 2.3 3.5 6b 3.6 3.6 6c 3.2 3.6 64 3.2 3.5 6: 3.4 3.5

it is evident from this table that addition of the compounds of the present invention results in a further increase of the blue density without lowering the red density in any case.

EXAMPLE Vll Following the processing steps of example i, but adding the compounds of the invention to the first developing solution instead of the prehardening bath, the following results were obtained:

Addition amount Test No. Additive to first developing (moi/liter) 7a no additive 7b -ethyl-3-mercapto-4-phenyl-l 2,4-triazole 5 10" 7c 3-mercapto-5-pentyI-4-phenyll 2,4-triazole SXIO" 7d 4-etliyI-3-mercapto-S-pllenybli 2.4-triazolc S IO" 7e 4,$-diethyl-3-mercaptol ,2.4-

triazole 5x I 0" As in example Vl, the photographic characteristic values resulting from the developing are shown as the blue density (DBmax) and red density (DRmax) in the following table.

Test No. Blue density (DBmax) Red density (DRmax) It is evident from this table that addition of the compounds of the present invention results in a further increase of the blue density without lowering the red density in any case.

EXAMPLE VIII A multilayer reversal color film having silver halide emulsion layers containing a color coupler and having three different sensitivity regions was exposed by a sensitometer and subjected to the following processing steps.

Processing steps Temperature ('C.) Time (min.)

First developing 37 3 First stopping 37 Is Water washing 37 1 Color developing 37 3% Second stopping 37 55 Water washing 37 l Bleaching 37 1% Fixing 37 1 Water washing 37 l The compositions of the processing solutions were as follows:

First developing solution sodium hexametaphosphate 1.0 g. l-phenyl-3-pyrazolidone 0.3 g. sodium sulfite 50.0 g hydroquinone 6.0 g. sodium carbonate monohydrate 35.0 g. potassium bromide 2.0 g. potassium thiocyanate 1.0 g. potassium iodide (0.l% aqueous solution) l0 ml. water to make L000 ml. First stopping solution and second stopping solution acetic acid 25 ml. sodium acetate 3 g. water to make L000 ml. Color developing solution sodium hexametaphosphate 1.0 g. benzyl alcohol 6.0 ml. sodium sulfite 5.0 g. sodium phosphate. tribasic 40.0 g. potassium bromide 0.2 g. potassium iodide (0.l% aqueous solution) l0.0 ml. sodium hydroxide 3.5 g. 4-amino-Il-rnethyI-N-ethyl-N- methanesulfonamideethylaniline sulfate 10.0 g. cthylenediamine 8.0 ml. water to make 1,000 mi. Bleaching solution potassium ferricyanide I00 g. potassium bromide 30.0 g. water to make 1.000 ml. Fixing solution sodium thiosulfate l50 g. sodium sulfito H) g. water to make 1.000 ml.

In the above internal-type reversal-developing treatment, a compound of the invention was added to the first developing solution. For comparison, a known fog inhibitor, 6-nitroisoindazole, was also used.

Addition amount The results are shown in the following table in which the photographic characteristic values are given by the blue density (DBmax) and red density (DRmax) on maximum density areas.

resulting from Test No. 8b, which is assigned a value of I00.

It is apparent from this table that the addition of the compounds of this invention results in a sufficiently high-blue density and improved image quality without affecting the sensitivity with good balancing of the blue and red densities. On the other hand, in the test using 6-nitroisoindazole as a known development inhibitor in place of the compounds of this invention for comparison, use of a small amount thereof does not increase the blue density, while use of a large amount thereof results in a very low-reversal sensitivity and does not provide a good image quality, although the blue density is increased. That is, 6-nitroisoinda2ole inhibits development of both the uppermost layer and the lowermost layer of the emulsion layers, thus lowering the reversal sensitivity. On the other hand, the compounds of the present invention selectively inhibit overdevelopment of the uppermost layer during high temperature processing, thus resulting in a well-balanced development without lowering the reversal sensitivity, as shown in the table.

EXAMPLE [X A multilayer color negative film having silver halide emul sion layers containing a color coupler and having three different sensitivity regions was exposed by a sensitometer and then subjected to the following processing steps.

The compositions of the processing solutions were as follows:

Color developing solution sodium hexametaphosphate 1.0 g. benzyl alcohol 5.0 g. sodium sulfite 3.0 g. sodium carbonate 41.0 g. sodium hydroxide 1.0 g. 4-amino-3-methyl-N-ethyl-N-methanesull'onamideethylaniline sulfate 50 g. potassium bromide 0.5 5. water to make l,000 ml. Stopping solution acetic acid 25 ml. sodium acetate 3 g. potassium alum I0 g. water to make 1.000. ml Bleaching solution potassium ferricyanide I00 g. potassium bromide 20.0 g. water to make L000 ml. Fixing solution sodium thiosulfate I50 g. sodium sulfite I0 g. water to make l,000 ml.

In the above color-negative-developing treatment, 5-ethyl- 3-mercapto-4-phenyl-l,2,4-triazole (m.p. 177 C.) of the present invention was added to the color developing solution in an amount of 5X 10" moi/liter.

A comparison of the results with those wherein no additive was present showed that the presence of 5-ethyl-3-mercapto-4 -phenyl-l,2,4-triazole (m.p. 177 C.) resulted in the blue-sensitive, green-sensitive and red-sensitive emulsions being developed with improved balance. In other words, excessive development of the blue-sensitive emulsion layer as the uppermost layer is avoided.

What is claimed is:

1. In a method for developing a sliver halide multilayer color photographic material selected from the group consisting of a color reversal film, a color negative film and a color paper, the improvement which consists essentially of treating said material with a developing solution consisting essentially of an aqueous solution of at least one developer and a development inhibiting compound represented by the formula:

in which R and R, are each selected from the group consisting of hydrogen, alkyl and wherein R, is selected from the group consisting of hydrogen, amino and 5. The method of claim 2 wherein said silver halide multilayer color photographic material is color reversal film and wherein said developer is at least one member selected from the group consisting of hydroquinone, l-phenyl-3- pyrazolidone and N-methyl-p-aminophcnol.

6. The method of claim 2 wherein said silver halide multilayer color photographic material is color negative film or color paper and wherein said developer is at least one p-phenylene-diamine derivative.

7. The method of claim 6 wherein said p-phcnylene-diamine derivative is at least one member selected from the group consisting of N,N-diethyl-p-phenylenediamine sulfite, N,N- diethyl-3-methyl-p-phenylenediamine hydrochloride, 4 amino-3-methyl-N-ethyl-N-methanesulfonamideethylaniline methyl-N-ethyl-N-methanesulfonamideethylaniline sulfate, 4- amino-3-methyl-N-ethyl-N-hydroxyethylaniline sulfate or N ethyl-N-hydroxyethyl-p-phenylenediamine sulfate.

8. The method of claim 1 wherein said alkyl group of R R and R has from one to 20 carbon atoms.

9. In a method for developing a silver halide multilayer color photographic material, the improvement which consists essentially of treating said material with a preprocessing solution consisting essentially of an aqueous solution of a compound which hardens gelatin and a development-inhibiting compound represented by the formula:

in which R and R are each selected from the group consisting of hydrogen, alkyl and wherein R is selected from the group consisting of hydrogen. amino and NH-C-R4' wherein R represents an alkyl group.

10. The method of claim 9 wherein said development inhibiting compound is a member selected from the group consisting of 3-mercapto-4-phenyl-,2,4-triazole, 3-mercapto-5- methyl-4-phenyl-l ,2,4-triazole, 5-ethyl-3-mercapto-4-phenyl- 1,2,4-triazole, 3-mercapto-5-pentyl-4-phenyll ,2,4-triazolc, 4,5-diphenyl-3-mercaptol ,2,4-triazole, 3-mercapto4-phcnyl-5-undecyll ,2,4-triazole, 4,5-diethyl-3-mercaptol ,2,4- triazole, 4-ethyl-3'mercapto-5-pentyl-1,2,4-triazole, 4-ethyl- 3-mercapto-5-phenyl-l ,2,4-triazole, 5-p-aminophenyl-4 ethyl-3-mercaptol ,2,4-triazole, 5-p-acet0amidephcnyl-4- ethyl-3-mercapto-l ,2,4-triazole, 5-p-caproamidephcnyl-4- ethyl-3-mercaptol ,2,4-triazo|e and 4-ethyl-5-p-lauroamidephenyl-3-mercapto-l ,2,4-triazole.

11. The method of claim 9 wherein said treatment is conducted at a temperature of from about 30 to about C.

12. The method of claim 9 wherein the concentration of said development-inhibiting compound in said aqueous solution varies from about l l0" mole per liter to about lXlO mole per liter.

13. The method of claim 9 wherein said compound which hardens gelatin is an aldehyde.

14. The method of claim 13 wherein said aldehyde is selected from the group consisting of formaldehyde, glyoxal, succinaldehyde, and glutaraldehyde.

15. The method of claim 9 wherein said aqueous solution further contains a salt, a buffering agent and a fog inhibitor.

16. The method of claim 15 w erein said salt is sodium sulfate, wherein said buffering agent is selected from the group consisting of borax, acetic acid, sodium acetate, sodium hydroxide, sodium carbonate, sulfuric acid and boric acid and wherein said fog inhibitor is an alkali metal halide.

17. The method of claim 9 wherein said alkyl of said R,, R and R has from one to 20 carbon atoms.

* k 1F t 

3. The method of claim 2 wherein said treatment is conducted at a temperature of from about 30 to about 70* C.
 4. The method of claim 2 wherein the concentration of said development-inhibiting compound in said aqueous solution varies from about 1 X 10 6 mole per liter to 1 X 10 2 mole per liter.
 5. The method of claim 2 wherein said silver halide multilayer color photographic material is color reversal film and wherein said developer is at least one member selected from the group consisting of hydroquinone, 1-phenyl-3-pyrazolidone and N-methyl-p-aminophenol.
 6. The method of claim 2 wherein said silver halide multilayer color photographic material is color negative film or color paper and wherein said developer is at least one p-phenylene-diamine derivative.
 7. The method of claim 6 wherein said p-phenylene-diamine derivative is at least one member selected from the group consisting of N,N-diethyl-p-phenylenediamine sulfite, N,N-diethyl-3-methyl-p-phenylenediamine hydrochloride, 4-amino-3-methyl-N-ethyl-N-methanesulfonamideethylaniline sulfate, 4-amino-3-methyl-N-ethyl-N-hydroxyethylaniline sulfate or N-ethyl-N-hydroxyethyl-p-phenylenediamine sulfate.
 8. The method of claim 1 wherein said alkyl group of R1, R2 and R4 has from one to 20 carbon atoms.
 9. In a method for developing a silver halide multilayer color photographic material, the improvement which consists essentially of treating said material with a preprocessing solution consisting essentially of an aqueous solution of a compound which hardens gelatin and a development-inhibiting compound represented by the formula:
 10. The method of claim 9 wherein said development inhibiting compound is a member selected from the group consisting of 3-mercapto-4-phenyl-,2,4-triazole, 3-mercapto-5-methyl-4-phenyl-1, 2,4-triazole, 5-ethyl-3-mercapto-4-phenyl-1,2,4-triazole, 3-mercapto-5-pentyl-4-phenyl-1,2,4-triazole, 4,5-diphenyl-3-mercapto-1,2,4-triazole, 3-mercapto-4-phenyl-5-undecyl-1,2,4-triazole, 4,5-dIethyl-3-mercapto-1,2,4-triazole, 4-ethyl-3-mercapto-5-pentyl-1,2,4-triazole, 4-ethyl-3-mercapto-5-phenyl-1, 2,4-triazole, 5-p-aminophenyl-4-ethyl-3-mercapto-1,2,4-triazole, 5-p-acetoamidephenyl-4-ethyl-3-mercapto-1,2,4-triazole, 5-p-caproamidephenyl-4-ethyl-3-mercapto-1,2,4-triazole and 4-ethyl-5-p-lauroamidephenyl-3-mercapto-1,2,4-triazole.
 11. The method of claim 9 wherein said treatment is conducted at a temperature of from about 30 to about 70* C.
 12. The method of claim 9 wherein the concentration of said development-inhibiting compound in said aqueous solution varies from about 1 X 10 6 mole per liter to about 1 X 10 2 mole per liter.
 13. The method of claim 9 wherein said compound which hardens gelatin is an aldehyde.
 14. The method of claim 13 wherein said aldehyde is selected from the group consisting of formaldehyde, glyoxal, succinaldehyde, and glutaraldehyde.
 15. The method of claim 9 wherein said aqueous solution further contains a salt, a buffering agent and a fog inhibitor.
 16. The method of claim 15 wherein said salt is sodium sulfate, wherein said buffering agent is selected from the group consisting of borax, acetic acid, sodium acetate, sodium hydroxide, sodium carbonate, sulfuric acid and boric acid and wherein said fog inhibitor is an alkali metal halide.
 17. The method of claim 9 wherein said alkyl of said R1, R2 and R4 has from one to 20 carbon atoms. 